50 The American Geologist. January, looi. 
Chemical Composition of Turquoise; by S. L. Pkm-ield, (Am. J. Sci. 
Z 60-346: 350.) 
The article records a re-investigation regarding the chemical com- 
position of turquoise. A new analysis was made on material exception- 
ally suitable for that purpose. From the results thus obtained the 
author shows conclusively that the mineral is to be regarded as a deriv- 
ative of the ortho-phosphoric acid in which the hydrogen atoms are 
largely replaced bj' the univalent, isomorphus radicals Al(OH)^ 
Fe(OH)', and Cu(OH)i. The formula may be written [Al(OH)-.., 
Fe(OH)o, Cu(OH), H]3 PO4. The radical AI(OH)^ always predomin- 
ates. A careful consideration of former anah'ses shows them to be in 
close agreement with the results just mentioned and wholly disproves 
Clark's interpretation that turquoise is a mixture of the molecule 
AloH PO4 (0H)4 with fineh' divided iron and copper phosphates as 
impurities. c. h. w. 
A new Meteorite from Oakley, Logan County, Kansas, by H. L. Pres- 
ton. (Am.J. Sci., ieO-410 412.) 
The meteorite, which is the eleventh one reported from Kansas, 
weighed 61 lbs. 10 oz. and was TH* x 10 x 12 inches in its greatest di- 
ameter. It consists of "olivine and enstatite chondrules imbedded in a 
very irregular groundmass of the same material, with numerous par- 
ticles of iron and iron sulphides." An analysis gives its composition as 
follows;— metallic part, Fe 12.76%; Ni + Co l.GSOo; silicates, 85.56%; 
lotal, lOOOo. c. H. w. 
Cambro- Silurian Limonite Ores of Pennsylvanta; bv T. C. Hopkins 
(Bull. Geol. Soc. Am., vol. 11, 475-502.) 
Extensive deposits of iron ores occur as irregular pocket-like de- 
posits in the residual clays of the Cambro-Ordovician limestones and 
slates of eastern and central Pennsylvania. The ores consist of the 
hydrous oxides of iron, chiefly limonite, associated with manganese 
ores, wavellite, quartz, chert and fluorite. The ores appear to have 
been derived from the original iron content of the limestones and slates, 
by a leaching and concentrating process in vvliich carbonic and 
organic acids together with oxygen took part. In position the ores 
favor the contact of the limestones and underlying slate. c. H. w. 
Chemical Composition of Sulphohalite: b^- S. L. Penfielij. (Am. J- Sci., 
160-425-428.) 
Considerable doubt as to the existence of the mineral sulphohalite 
recently described and assigned the formula 3 Na^ SO4 2NaCl, having 
arisen by reason of the failure of several investigators to make an arti- 
ficial salt of like composition, there-investigation of the species described 
in this article was undertaken with the result that another constituent, 
fluorine, was discovered and the composition represented by the formula 
2 Nao SO4, 2 Na ClNaF assigned to the mineral. It is interesting to note 
that sulphohalite was associated with another triple salt, the mineral 
hanksite 9 Nag SO4 2 Nag CO3 K CI. c. h. w. 
